With the development of semiconductor lighting technology, such revolutionary new light source, i.e. LED (light emitting diode), has come into our daily life gradually. As a new-type lighting technology, LED can be applied into varieties of fields such as indication, display, decoration, backlight and general lighting due to its numerous advantages including energy conservation, green environmental protection and flexible application etc. When the third generation semiconductor material gallium nitride is used as the semiconductor lighting source, its power consumption is only one-tenth of that of a common incandescent lamp under the same brightness, and its lifetime can reach more than 100,000 hours as well, which is to bring about a revolution in the lighting field.
At present, most commercial white light LED lighting devices are realized by the cooperation between blue light LED chips and fluorescent powders which are capable of emitting yellow, green or orange light when excited by blue light. Such kind of fluorescent powder luminescent material has higher luminous efficiency and matured preparation method. However, the light source devices manufactured by this method has the following drawbacks: (1) the epoxy resin for encapsulation is easy aging, thus reducing the device lifetime; (2) its process is complex and cost is high; (3) the color coordinate is unstable and the white light is easy to drift.
Compared with a fluorescent powder, the glass that can achieve a light emission when excited by the blue-purple light has the following significant advantages: (1) excellent transmittance; (2) excellent chemical stability and thermostability; (3) simple preparation process and low cost; (4) easily made into big bulk and different shapes; (5) capable of replacing the epoxy resin. Since these features, the glass capable of achieving a high-performance luminescence is very suitable as the luminescent material in the LED lighting field.
However, for the light emitting glass in the existing technology, many light-emitting active ions in the glass has very low luminous intensity or can not even shine since the limitation of glass preparation condition and glass structure.